EP0074021B1 - Appareil d'examen radiologique - Google Patents

Appareil d'examen radiologique Download PDF

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Publication number
EP0074021B1
EP0074021B1 EP82107827A EP82107827A EP0074021B1 EP 0074021 B1 EP0074021 B1 EP 0074021B1 EP 82107827 A EP82107827 A EP 82107827A EP 82107827 A EP82107827 A EP 82107827A EP 0074021 B1 EP0074021 B1 EP 0074021B1
Authority
EP
European Patent Office
Prior art keywords
hollow cylinder
examination apparatus
ray examination
ray
supporting plate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP82107827A
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German (de)
English (en)
Other versions
EP0074021A1 (fr
Inventor
Alfred Arauner
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Original Assignee
Siemens AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens AG filed Critical Siemens AG
Publication of EP0074021A1 publication Critical patent/EP0074021A1/fr
Application granted granted Critical
Publication of EP0074021B1 publication Critical patent/EP0074021B1/fr
Expired legal-status Critical Current

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/06—Diaphragms
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K1/00—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating
    • G21K1/02—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating using diaphragms, collimators
    • G21K1/04—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating using diaphragms, collimators using variable diaphragms, shutters, choppers

Definitions

  • the invention relates to an x-ray examination device with a patient support plate, with an x-ray tube arranged on one side of the patient support plate, with a primary beam blanking device which produces a narrowly faded-out pivotable x-ray beam in one plane and with a detector arrangement arranged on the other side of the patient support plate and exposed to the beam .
  • An X-ray examination device has already become known in which the beam cone emerging from an X-ray tube is fanned in by a slit diaphragm and in which a radially slotted circular diaphragm disk made of radiopaque material is rotatably mounted in a plane perpendicular to the beam direction behind the slit diaphragm in the beam direction (US A-3 780 291).
  • the beam which is masked out in this way and is pencil-strong, moves from one side to the other when the aperture disk is rotated in the fan plane.
  • a detector arrangement is assigned to this beam behind the examination object. When moving the X-ray examination device perpendicular to the fan plane, one slice of the examination object can be scanned after the other.
  • the measured values of the individual detectors arranged line by line can be stored and displayed line by line in different gray levels on a television viewing device.
  • the image corresponds to a conventional x-ray.
  • the proportion of scattered radiation is small because of the relatively small volume penetrated by X-rays.
  • the diaphragm disc must also have a significantly larger diameter than the width of the masked beam fan in the plane of the diaphragm disc. This leads to the fact that the entire blanking arrangement becomes so bulky that it is only at. Under-table tube devices can be used. But even there it shows that only part of the longitudinal stroke can be used when moving in the longitudinal direction of the table, because otherwise the slotted diaphragm disc would abut the front of the table frame.
  • US Pat. No. 4,266,135 shows a computer tomograph in which a fan-shaped beam of rays is used to irradiate the examination object, which can also consist of individual beams that diverge in a finger shape.
  • the width of the fan-shaped beam of rays can be changed by means of an aperture.
  • the object of the invention is to enlarge the examination area in the case of X-ray examination devices which scan the examination object in a line shape with a closely masked X-ray beam.
  • a constructive solution is also to be found which makes it possible to work with such an X-ray examination device by reversing the direction of the radiation with an upper table X-ray tube and a lower table receiving device.
  • the masking device contains a uniformly driven hollow cylinder with its axis of symmetry oriented approximately perpendicular to the beam direction, the radiopaque wall of which carries two spiral slots offset by 180 ° from one another such that the hollow cylinder between the radiation source and the patient support plate are mounted at a distance from the focus at the end of a funnel-like holder corresponding to the fan-shaped beam, the cross section of which is filled by the hollow cylinder, and that an additional slit-shaped insertion near the focus is arranged in the plane given by the focus and the axis of symmetry of the hollow cylinder.
  • Such a hollow cylinder allows the radiation to pass only in the area in which the two slots on the front and rear side of the lateral surface in the beam direction are in line with the focus. This is always the case in only one point. This point moves in the axial direction when the hollow cylinder rotates.
  • the hidden beam has a rhombic cross-section. It is a major advantage of this construction that the blanking device takes up little space perpendicular to the fan plane. When used with an under-table X-ray tube, the longitudinal stroke underneath the table frame is not hindered. For the same reason this fade out is suitable Direction also particularly for X-ray examination devices in which the X-ray tube together with the blanking device are above and the detectors below the patient support plate.
  • the construction according to the invention reduces the formation of penumbra and at the same time prevents stray radiation from escaping in the area of the masking device.
  • the additional, slit-shaped fade-in close to the focus further reduces the scattered radiation and increases the sharpness of the blanked-out beam.
  • the blanking device can also be used for larger fan angles if, in a particularly advantageous development of the invention, the slot width is widened from the slot center to its ends. This has the advantage that even in the case of the oblique radiation of the hollow cylinder at both ends, the different axially displaced point of incidence of the beam on the side facing the radiation source and the side of the hollow cylinder facing away from it does not lead to any narrowing of the transmitted beam.
  • the radiation exposure of the patient can be reduced even further if, in a particularly expedient development of the invention, an aperture plate is inserted into the beam path between the X-ray tube and the patient support plate, which bores are aligned with the individual detector elements of the detector arrangement. As a result, each individual detector element is irradiated separately while the intermediate zones are protected.
  • FIG. 1 shows the structure of the X-ray examination device 1.
  • a well-transparent patient support plate 3 is supported on a table frame 2. It can be moved in the longitudinal direction of the table.
  • a stand column 4 is mounted displaceably in the longitudinal direction of the table.
  • the stand column carries an X-ray tube 6 on a horizontal support arm 5 under the patient support plate 3.
  • the blanking device 7 according to the invention is attached to this.
  • the tripod column 4 carries above the patient support plate 3 a detector arrangement 9, which is exposed to the beam 8 emerging from the masking device, with individual detectors 11, 12, 13, 14 arranged closely next to one another.
  • the tripod column 4 is longitudinal at a constant speed via a drive motor 15 the patient support plate 3 slidably.
  • the masking device 7 has a tube-like holder 16 fastened to the tube flange, which carries at its end near the focus a slot diaphragm 18 which can be inserted in the exemplary embodiment through an insertion slot 17.
  • slit diaphragm 18 consists of a simple rectangular plate 19 made of radiopaque material, which is provided with a longitudinal slot 20 of constant width.
  • the tube-like holder 16 Corresponding to the fan-shaped beam cone emerging from the slit diaphragm 18, the tube-like holder 16 also has a narrow, rectangular, fan-shaped cross section.
  • a hollow cylinder 21 is rotatably mounted on the tube-like holder such that its axis of symmetry 22 lies exactly in the plane formed by the slit 20 of the slit diaphragm 18 and the focus 23 of the X-ray tube 6 becomes.
  • the axis of symmetry 22 of the hollow cylinder 21 is oriented approximately perpendicular to the beam direction.
  • the diameter of the hollow cylinder 21 - approximately 15 cm in the exemplary embodiment - completely fills the cross section of the tubular holder 16.
  • the tubular holder in the exemplary embodiment in FIG. 1 is only shown as far as the hollow cylinder 21. It could be expedient to extend the tube-like holder beyond the hollow cylinder to just below the patient support plate.
  • the jacket 24 of the hollow cylinder 21 has, as shown in FIG. 1, two spiral slots 25, 26. Their shape can be seen in the development of the jacket 24 of the hollow cylinder 21 shown in FIG.
  • the jacket of the hollow cylinder consists of a radiopaque plate in which the two slots 25, 26 are arranged one behind the other at an angle of approximately 45 ° to the lateral boundary.
  • the two slots are widened somewhat at each end like a club (Fig. 3).
  • the hollow cylinder is driven uniformly by the drive motor 15. At the same time, this also shifts the stand column 4 relative to the patient support plate 3 via a gear mechanism. This shift can be selected such that the drive motor shifts the stand column by one full revolution of the hollow cylinder 21 by the width of the beam 8. The speed of the drive motor per unit of time should. can be varied to adapt to the tube performance.
  • a fan-shaped beam 8 is blocked out by the slit diaphragm 18 near the focus.
  • This fan-shaped beam of rays strikes the other side of the tube-like holder on the hollow cylinder 21 rotatably mounted there in the plane of its axis of symmetry 22.
  • the X-ray Radiation can only penetrate the hollow cylinder in that area of the two slots 25, 26 in which the slot on the side of the hollow cylinder facing away from the focus and the slot on the side facing the focus of the hollow cylinder are in a straight line with the focus or otherwise expressed overlapping from the point of view of focus. This is only the case in a narrow rhombus-shaped area.
  • the beam 8 thus blocked out penetrates the patient support plate 3, the examination object lying on the patient support plate 3 and then strikes the detector arrangement 9.
  • the slit diaphragm 18 near the focus only reduces the scattered radiation which arises between the slit diaphragm and the hollow cylinder and thus the proportion of scattered radiation which can pass through the overlapping slits 25, 26 on both sides of the hollow cylinder.
  • the slit of the slit diaphragm close to the focus is therefore also held somewhat further than the beam 8 passing through the hollow cylinder.
  • a fluoroscopic image of the examination object can be constructed which corresponds to a conventional X-ray image. Because of the low volume of radiation, however, the amount of scattered radiation is smaller and the contrast is greater than with conventional X-ray images.
  • the sharpness of the drawing grows inversely proportional to the diameter of the masked beam 8 and the distance between the individual radiation detectors. It can be increased if the advance of the stand column corresponds to only half a diameter of the blanked beam bundle instead of an entire diameter during a half revolution of the hollow cylinder 21.
  • each scanned slice of the examination object overlaps with the following slice by half a beam width.
  • a further increase in the sharpness of the drawing can be achieved if the detector arrangement is shifted by half a detector width in the direction of the detector line after each scanned line.
  • a further insertion slot 27 is provided in the tube-like holder 16 in the immediate vicinity of the hollow cylinder 21 for a perforated diaphragm plate 28 shown in FIG. 4.
  • This perforated diaphragm plate is made of a radiation-impermeable material and carries a row of holes 29 in the plane of the fan beam which is blocked by the slit diaphragm close to the focus.
  • These holes are arranged in such a way that each of them, when the diaphragm plate 28 is fully inserted, leads to a detector element 10, 11, 12 , 13, 14 of the detector arrangement 9 is aligned. This ensures that when the detector array 9 is swept over the area between two detectors, the beam 8 is masked out and only those X-ray quanta that penetrate the body of the examination object that later also contribute to the image information pass through.
  • the perforated diaphragm plate shown in FIG. 4 is also possible to arrange the perforated diaphragm plate shown in FIG. 4 on the side of the hollow cylinder 21 facing away from the focus. As a result, the formation of penumbra is reduced because of the larger focal distance of the perforated diaphragm plate 28. If a linear displacement of the detectors by half a detector width is provided after each line scanned, the perforated diaphragm plate must also be displaced synchronously with the detectors by half a hole spacing. By changing the speed of the drive motor 15, the signal level of the individual detectors 10, 11, 12, 13, 14 of the detector arrangement can be adapted to the dose rate of the X-ray tube 6. It is also possible to move the patient support plate 3 with the examination object with the drive motor instead of the stand column 4.
  • the dimensions of the blanking device can be so small compared to the previously known solution that a reversal of the beam direction is easily possible if the x-ray tube with the blanking device is attached to the stand column 4 above the patient support plate and the detector arrangement below the patient support plate.

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  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Medical Informatics (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Optics & Photonics (AREA)
  • Biomedical Technology (AREA)
  • General Engineering & Computer Science (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Pathology (AREA)
  • Radiology & Medical Imaging (AREA)
  • Biophysics (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Apparatus For Radiation Diagnosis (AREA)

Claims (9)

1. Appareil d'examen radiologique comportant un plateau (3) formant couchette pour patient, un tube à rayons X (6) situé d'un côté du plateau (3) formant couchette pour patient, un dispositif (7) de collimation du rayonnement primaire, produisant un faisceau de rayons X (8) étroitement collimaté et pouvant pivoter en forme d'éventail dans un plan, et un dispositif de détection (9) disposé d'un côté du plateau (3) formant couchette pour patient et soumis à l'action du faisceau de rayonnement (8), caractérisé par le fait que le dispositif de collimation (7) comporte un cylindre creux (21) dont l'axe de symétrie (22) est approximativement perpendiculaire à la direction du rayonnement et qui est entraîné de façon uniforme et dont la paroi (24) opaque au rayonnement comporte deux fentes (25, 26) de forme hélicoïdale, décalées de 180° l'une par rapport à l'autre, que le cylindre creux (21) est monté entre la source de rayonnement (23) et le plateau (3) formant couchette pour patient, dans une position éloignée du foyer, à l'extrémité d'un support (16) en forme de trémie, qui correspond au faisceau de rayonnement en forme d'éventail et dont la section transversale est remplie par le cylindre creux (21), et qu'un dispositif supplémentaire de collimation en forme de fente (18, 20) proche du foyer, est disposé dans le plan déterminé par le foyer (23) et par l'axe de symétrie (22) du cylindre creux (21).
2. Appareil d'examen radiologique suivant la revendication 1, caractérisé par le fait que la largeur de la fente augmente depuis le milieu de cette dernière en direction de ses extrémités.
3. Appareil d'examen radiologique suivant la revendication 1, caractérisé par le fait qu'un volet de diaphragme (28), qui comporte des trous (29) alignés sur les différents éléments détecteurs (10, 11, 12, 13, 14) du dispositif de détection, est inséré sur le trajet du rayonnement entre le tube à rayons X (6) et le plateau (3) formant couchette pour patient.
4. Appareil d'examen radiologique suivant la revendication 3, caractérisé par le fait que le volet de diaphragme (28) est inséré, sur le trajet du rayonnement, directement en arrière du cylindre creux (21).
5. Appareil d'examen radiologique suivant la revendication 3, caractérisé par le fait que le dispositif de détection (9) comporte une série de détecteurs individuels (10, 11, 12, 13, 14), disposés en étant serrés les uns à côté des autres, dans le plan de l'éventail, qui est balayé par le faisceau de rayonnement (9).
6. Appareil d'examen radiologique suivant la revendication 1, caractérisé par le fait que le tube à rayons X (6), le dispositif (7) de collimation du rayonnement primaire et le dispositif de détection (9) peuvent être déplacés en commun, à une vitesse constante, transversalement à l'axe de symétrie (22) du cylindre creux (21) et à la direction du rayonnement, par rapport au plateau (3) formant couchette pour patient.
7. Appareil d'examen radiologique suivant la revendication 6, caractérisé par le fait que le dispositif d'entraînement servant à réaliser le déplacement du plateau formant couchette pour patient par rapport au reste de l'appareil (1) d'examen radiologique et le dispositif (15) d'entraînement du cylindre creux (21) sont accouplés entre eux en vue d'obtenir un balayage suivant des lignes étroitement rapprochées les unes des autres.
8. Appareil d'examen radiologique suivant la revendication 7, caractérisé par le fait que le plateau (3) formant couchette pour patient se déplace, lors de chaque rotation du cylindre creux (21), sur une distance égale approximativement à la largeur du faisceau de rayonnement (8), par rapport au reste de l'appareil (1) d'examen radiologique.
9. Appareil d'examen radiologique suivant la revendication 1, caractérisé par le fait que les fentes (25, 26) font, sur la projection développée (24) du cylindre creux (21), un angle de 45° avec le bord latéral de cette projection développée.
EP82107827A 1981-09-07 1982-08-25 Appareil d'examen radiologique Expired EP0074021B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3135421 1981-09-07
DE19813135421 DE3135421A1 (de) 1981-09-07 1981-09-07 Roentgenuntersuchungsgeraet

Publications (2)

Publication Number Publication Date
EP0074021A1 EP0074021A1 (fr) 1983-03-16
EP0074021B1 true EP0074021B1 (fr) 1985-11-21

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Family Applications (1)

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EP82107827A Expired EP0074021B1 (fr) 1981-09-07 1982-08-25 Appareil d'examen radiologique

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EP (1) EP0074021B1 (fr)
JP (1) JPS5850941A (fr)
DE (2) DE3135421A1 (fr)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3443095A1 (de) * 1984-11-27 1986-05-28 Philips Patentverwaltung Gmbh, 2000 Hamburg Anordnung zur untersuchung eines koerpers mit gamma- oder roentgenstrahlung
US4879345A (en) * 1988-07-27 1989-11-07 Ppg Industries, Inc. Fluoropolymer based coating composition for adhesion direct to glass
DE3829688A1 (de) * 1988-09-01 1990-03-15 Philips Patentverwaltung Anordnung zur erzeugung eines roentgen- oder gammastrahls mit geringem querschnitt und veraenderlicher richtung
US5008153A (en) * 1988-12-08 1991-04-16 Ppg Industries, Inc. Corrosion inhibitive pretreatment for "copper-free" mirrors
DE3908966A1 (de) * 1989-03-18 1990-09-20 Philips Patentverwaltung Anordnung zur erzeugung eines roentgen- oder gammastrahls mit geringem querschnitt und veraenderbarer lage
DE60222768T2 (de) 2001-04-03 2008-07-17 Koninklijke Philips Electronics N.V. Computertomograph
DE102005048519A1 (de) * 2005-10-06 2007-04-19 BAM Bundesanstalt für Materialforschung und -prüfung Brennpunktorientierte Blende
US10082473B2 (en) 2015-07-07 2018-09-25 General Electric Company X-ray filtration
CN110507351A (zh) * 2019-08-13 2019-11-29 孙立磊 一种放射科用新型影像检查辅助装置

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3780291A (en) * 1971-07-07 1973-12-18 American Science & Eng Inc Radiant energy imaging with scanning pencil beam
US4031401A (en) * 1975-03-14 1977-06-21 American Science & Engineering, Inc. Radiant energy imaging scanning
US4266135A (en) * 1977-07-01 1981-05-05 Ohio Nuclear, Inc. Method of determining collimator aperture efficiency and apparatus with an efficient collimator aperture size
DE2932182A1 (de) * 1979-08-08 1981-02-26 Siemens Ag Schichtgeraet zur herstellung von transversalschichtbildern
GB2076250A (en) * 1980-05-19 1981-11-25 American Science & Eng Inc Mechanical X-ray scanning

Also Published As

Publication number Publication date
JPS5850941A (ja) 1983-03-25
DE3267605D1 (en) 1986-01-02
EP0074021A1 (fr) 1983-03-16
DE3135421A1 (de) 1983-03-24

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